import java.util.Arrays;

class Bird{
    public String name;  //成员属性
    public String sex;   //成员属性

    public void func() {   //成员方法
        System.out.println("我是成员方法");
    }
}

public class TestDemo {
    public static String toLowerCase(String s) {
        StringBuilder sb = new StringBuilder();
        char[] a = s.toCharArray();
        for(int i = 0;i < a.length;i++) {
            if(a[i] <='Z' && a[i] >='A') {
                sb.append((char)(a[i]+32));
            } else {
                sb.append(a[i]);
            }
        }
        return sb.toString();
    }

    public static void main(String[] args) {
        String s = "Hello";
        String s1 = toLowerCase(s);
        System.out.println(s1);

    }
    public static void main3(String[] args) {
        int count = 0;
        String str = " , , , , ,   a, aaa";
        String[] s = str.split(" ");
        for (String s1:s) {
            if(!"".equals(s1)) {
                count++;
            }
        }
        System.out.println(count);
    }

    public static void main2(String[] args) {
        String[] array = {"abc","ab","cab","abcd"};
        Arrays.sort(array);
        System.out.println(array.toString());
    }
    public static void main1(String[] args) {
        Bird bird1 = new Bird();
        bird1.name = "小黄鸟";
        Bird bird2 = new Bird();
        bird2.name = "小白鸟";
        Bird bird3 = new Bird();
        System.out.println(bird1.name);
        System.out.println(bird2.name);
        System.out.println(bird3.name);
    }
}
